The Justice Department is appealing a judge's decision to order a new trial for five former New Orleans police officers convicted of civil rights violations stemming from deadly shootings on a bridge after Hurricane Katrina.

Prosecutors filed a notice of appeal late Thursday, asking the 5th U.S. Circuit Court of Appeals to review last month's decision by U.S. District Judge Kurt Engelhardt.

Engelhardt threw out the former officers' convictions, concluding the case had been tainted by "grotesque prosecutorial misconduct." The judge said at least three government attorneys posted anonymous comments on a New Orleans newspaper's website, creating a "carnival atmosphere" that perverted justice in the case.

Police shot and killed two unarmed people and wounded four others on the Danziger Bridge less than a week after the 2005 storm.